The invention concerns a camera for reproducing prints or transparencies, known as a reprography camera, with a copy table or production table such that longitudinal displacement of the lens results in a change in the size or proportion of the picture. This reprography camera also has a stationary image platform and a mirror which deflects the light path from the copy table to the lens.
The conventional construction of a reprography camera allows the option of producing copies in various predetermined sizes and fixed formats. The size of the resulting copy necessitates a change in the original proportion and this change can only be achieved through an adjustment of the lens in the light path relative to the image platform and the original copy. Although the optical centerpoint remains on the copy table, it does not remain equally so on the image platform as the lens is longitudinally displaced. These points lag even further from each other as the lens is further displaced.
The practical result of this optical lag is that the middle of a copy which is a different size from the original copy must be laterally aligned opposite the middle of the original copy. Since the displacement of the optical middle does not linearly follow a change in the image size, e.g., a lateral displacement of the center of the copy may even produce a reversal point, the copy tables of the prior art are not reliably marked as to how a copy of a determined size must be positioned on the copy table in order to fill the copy area of the image platform as desired.